Patisiran

Patisiran, sold under the brand name Onpattro, is a medication used for the treatment of polyneuropathy in people with hereditary transthyretin-mediated amyloidosis, a fatal rare disease that is estimated to affect 50,000 people worldwide.

It is the first small interfering RNA-based drug approved by the U.S. Food and Drug Administration (FDA) and the first drug approved by the FDA to treat this condition. It is a gene silencing drug that interferes with the production of an abnormal form of transthyretin. Patisiran utilizes a novel approach to target and reduce production of the TTR protein in the liver via the RNAi pathway.

Patisiran was developed and is marketed by Alnylam. The FDA considers it to be a first-in-class medication.

History
Patisiran was granted orphan drug status, fast track designation, priority review and breakthrough therapy designation due to its novel mechanism and the rarity of the condition it treats. It was approved for medical use in the United States and in the European Union in August 2018. The per-patient cost is between US$451430 and US$677145 per year, depending on the number of vials needed.

Formulation
The siRNA active component of Patisiran is formulated into lipid nanoparticles, which protect the RNA and facilitate its delivery to target tissues. The lipid nanoparticle formulation includes buffer components, as well as the lipid components DLin-MC3-DMA, Distearoylphosphatidylcholine, cholesterol, and the PEGylated lipid DMG-PEG 2000.

Economics
As of 2020, there were 1050 people globally receiving patisiran, generating $65.5M in net-revenues for Alnylam Pharmaceuticals.